Displaying a message when registering to another page?

Question

Web development

Hello. I can not make a competent output of the message about successful registration. Please help.
When I register, this data is sent to a file to check if there is such an account. After verification, that verification file opens in the browser and writes "You are registered."

<?php
if(createAccount($login, $mdp, $mail)){
echo("You are registered!");
exit();
}
?>

But, I need it not to go to the file with the check and not give out this inscription on a white background. I need it to give out where I registered (it can be some kind of pop-up window, or in the same block with registration)
The bottom line is that I don’t know how to do it. Please help

Answer 1

Ajax(@lidacriss) has already been suggested.
You can also use redirection to the page with
registration success, but it is more logical to launch it in your personal account.
Those. if the registration was successful, we automatically authorize
and send it to the place where it was required.
This can be a personal account, a shopping cart, a
news page from which a person went to registration in order to leave a comment.